human ecology report.pptx

Human ecology

1. Meaning of Ecology

2. Some definitions of Ecology: Charles Elton (1927)- wrote the book “Animal Ecology”. In this book, he defined ecology as “the study of the scientific natural history”.

3. Eugene P. Odum (1963)- defined ecology as “ the study of the structure and function of nature”. Some definitions of Ecology:

4. Andrewartha (1961)- also gave a clear and restrictive definition of ecology: Ecology is the scientific study of the distribution and abundance of organisms . Some definitions of Ecology:

5. Charles J. Krebs (1985)- gave a precise definition of ecology based on the modification of Andrewartha’s definition: Ecology is the scientific study of the interactions that determine the distribution and abundance of organisms . Some definitions of Ecology:

6. Ecology Is the scientific study of the interactions between organisms and their environment. The word ecology originated from two G reek words; oikos and logos. Oikos = “household”, “home” or “place to live” Logos = “knowledge”, “study”

7. Meaning of Human Ecology

8. Human Ecology Is an academic discipline that deals with the association between humans and their natural environment.

9. The main task of human ecology… The investigation of human health condition The research of dynamics of human health condition in the process of historical and socio-economical development The determination of correlative dependence between human diseases and environmental pollution; The investigation of the processes of human health protection

10. Human Natural History and Environment

11. 4 Main Theories of Evolution Lamarckism or Theory of Inheritance of Acquired characters Darwinism or Theory of Natural Selection Mutation Theory of De Vries Neo-Darwinism

12. 1. Lamarckism Also called “theory of inheritance of acquired characters” and was proposed by a great French naturalist, Jean Baptiste de Lamarck in 1809 A.D. in his famous book “Philosophic Zoologique ”. This theory is based on the comparison between the contemporary species of his time to fossil records.

13. Summary of Four P ostulates of Lamarckism: Living organisms or their component parts tend to increase in size. Production of new organ is resulted from a new need. Continued use of organ makes it more developed, while disuse of an organ results in degeneration. Acquired characters developed by individuals during their own lifetime are inheritable and accumulate over a period of time resulting to a new species.

14. Criticism of Lamarckism: A hard blow to Lamarckism came from a German Biologist, August Weisman who proposed the “Theory of continuity of germplasm ” in 1982 A.D. this theory states that environmental factors do affect only somatic cells and not the germ cells.

15. Significance: It was the first comprehensive theory of biological evolution. It stressed on adaptation to the environment as primary product of evolution.

16. 2. Darwinism Also called Theory of Natural Selection Charles Darwin (1809-1882 A.D.) an English naturalist, was the most dominant figure among the biologist of the 19 th century. He made an extensive study of nature for over 20 years, especially in 1831-1836. In 1858 A.D., Darwin was highly influenced by short essay entitled “On the Tendency of Varieties to Depart Indefinitely from the Original Types” written by another naturalist, Alfred Russel Wallace (1892-1913) who studied biodiversity on Malayan archipelago and came to similar conclusions.

17. Darwin and Wallace’s views about evolution were presented in the meeting of Linnean Society of London by Lyell and Hooker on July 1, 1858. Darwin’s and Wallace’s work was jointly published in “Proceeding of Linean Society of London” in 1859. So it also called Darwin-Wallace Theory. Darwin explained his theory of evolution in book entitled “On the Origin of Species by means of Natural Selection”. It was published on the 24 th Nov., 1859. in this theory, Charles Darwin proposed the concept of natural selection as the mechanism of evolution.

18. Postulates of Darwinism: Geometric increase Limited food and space Struggle for existence Variations Natural selection or survival of the fittest In heritance of useful variations S peciation

19. 1. Geometric Increase According to Darwinism, the populations tend to multiply geometrically and the reproductive power of living organisms are much more than required to maintain their number.

20. 2. Limited food and space Darwinism states that through a population tends to increase geometrically , the food increases only arithmetically .

21. 3. Struggle for existence Due to rapid multiplication of populations but limited in food and space, there starts and everlasting competition between individuals having similar requirements. 3 types of Struggle for Existence Intraspecific- between the member of the same species Interspecific- between the members of different species Extra specific or environmental- between living organism and adverse environmental factors.

22. 4. Variations Darwin stated that the variations are generally of two types- continuous variations and discontinuous variations. Darwin proposed that living organisms tend to adapt to changing environment due to useful continuous variations (e.g., increased in speed, increased in water conservation in plants) as these will have a competitive advantage.

23. 5. Natural selection Darwin stated that as many selects the individuals with desired characters in artificial selection; nature selects only those individuals out of the population which are with useful continuous variations and are best adapted to the environment while the less fit or unfit individuals are rejected by it. Darwin stated that if the man can produce such a large number of new species/varieties with limited resources and in short period of time by artificial selection, then natural selection could account for this large biodiversity by considerable modifications of species with the help of unlimited resources available over long span of time.

24. Darwin stated that discontinuous variations appear suddenly and will mostly be harmful, so are not selected by nature. He called them “sports”. So the natural selection is an automatic and self going process and keeps a check on the animal population. This sorting out of the individuals with useful variations from a heterogeneous population by the nature was called Natural selection by Darwin and Survival of the fittest by Wallace. So natural selection acts as a restrictive force and not a creative force .

25. 6. Inheritance of useful variations Darwin believed that the selected individuals pass their useful continuous variations to their offsprings so that they are born fit to the changed environment.

26. 7. Speciation According to Darwinism, useful variations appear in every generation and are inherited from one generation to another. So the useful variations go on accumulating and after a number of generations, the variations become so prominent that the individual turns into a new species. So according to Darwinism, evolution is a gradual process and speciation occurs by gradual changes in the existing species.

27. Evidence in favour of Darwinism: There is a close parallelism between natural selection and artificial selection. The remarkable cases of resemblance e.g. mimicry and protective coloration can be achieved only by gradual changes occurring simultaneously both in the model and the mimic. Correlation between position of nectaries in the flowers and length of the proboscis of the pollinating insect.

28. Evidence against Darwinism: Darwinism is not able to explain: 1. The inheritance of small variations in those organs which can be of use only when fully formed e.g. wing of a bird. Such organs will be of no use in incipient or underdeveloped stage. 2. Inheritance of vestigial organs. 3. Inheritance of over-specialized organs e.g. antlers in deer and tusk in elephants 4. Presence of neuter flower and sterility of hybrids.

29. 5. Did not differentiate between somatic and germinal variations. 6. He did not explain the causes of the variations and the mode of transmission of variations. 7. It was also refuted by Mendel’s laws of inheritance which state that inheritance is particulate

30. So, this theory explains only the survival of the fittest but does not explain the arrival of the fittest so Darwin himself confessed , ”Natural selection has been main but not the exclusive means of modification”.

31. 3. Mutation Theory of Evolution: The mutation theory of evolution was proposed by a Dutch Botanist, Hugo de Vries (1848-1935 A.D.), in 1901 A.D. in his book entitled “Species and Varieties, Their Origin by Mutation”. He conducted his experiment on Oenothera Lamarckiana in botanical gardens at Amsterdam. The plants were allowed to self pollinate and next generation was obtained. The plants of next generation were again subjected to self pollination to obtain second generations. Process was repeated for a number of generations.

32. Evidences in favour of Mutation Theory: Appearance of a short-legged sheep variety, Ancon Sheep, from long-legged parents in a single generation in 1791 A.D.. It was first noticed in a ram by an American farmer, Seth Wright .

33. Mutation theory can explain the origin of new varieties or species by a single gene mutation It can explain the inheritance of vestigial and over-specialized organs. It can explain progressive as well as retrogressive evolution.

34. Evidences against Mutation theory: . Rate of mutation is very low, (one per million or one per several million genes) Oenothera lamarckiana is a hybrid plant and contains anamolous type of chromosome behaviour. Chromosomal numerical changes as reported by de Vries are unstable. Mutations are incapable of introducing new genes and alleles into a gene pool.

35. 4. Neo-Darwinism or Modern Concpet of Syntghetic Theory of Evolution: Modern or synthetic theory of evolution was designated by Huxley (1942). It emphasizes the importance of populations as the units of evolution and the central role of natural selection. The scientist who contributed to the outcome of Neo- Darwimism were: J.S. Huxley, R.A. Fischer and J.B.S. Haldane of England; and S. Wright, Ford, H.J. Muller and T. Dobzhansky of America.

36. Summary Postulates of Neo- Dawinsim : Neo-Darwinism is a modification of the original theory of Darwin to remove its short-comings. Instead of continuous variations, mutations are believed to help form new species. Variations accumulate in the gene pool and not in the individuals. Neo-Darwinism incorporates isolation as an essential component of evolution.

37. What is the significance of Environment in the Human Natural History?

38. As the environment changes, the organisms continuously change, eventually causing to evolve into a new species.

39. Basic World Geography

40. What is Geography? Is the spatial study of the earth’s surface. From the two Greek words “geo” and “ graphein ” Geo = Earth Graphein = to write

41. Two main areas of Geography: Physical Geography Human Geography

42. 1. Physical Geography Is the spatial study of natural phenomena that make up the environment such as rivers , mountains , landforms , weather , climate , soils , plants , and any other physical aspects of the earth’s surface.

43. The major forms of study within physical geography include the following: Geomorphology- the study of the earth’s surface Glaciology - the study of glaciers Coastal geography- the study of the coastal regions Climatology- the study of climates and climate change Biogeography - the study of the geographic patterns of species distribution

44. Physical Landscape Is the term used to describe the natural terrain at any one place on the planet. The natural forces of erosion, weather, tectonic plate action, and water have formed the earth’s physical features.

45. 2. Human Geography Is the study of human activity and its relationship to the earth’s surface. Human geographers examine the spatial distribution of human populations, religions, languages, ethnicities, political systems, economics, urban dynamics and other components of human activity.

46. Cultural Landscape I s the term used to describe those parts of the earth’s surface that have been altered or created by humans. Urban Cultural Landscape- buildings, streets, signs, parking lots, vehicles… Rural Cultural Landscape- fields, orchards, fences, barns, farm steads…

47. Basic concepts in Geography Island- it is any piece of sub-continental land that is surrounded by water. Peninsula - a body of land surrounded by water on three sides. Comes from the Latin word “ paene insula” meaning “almost an island”.

48. Strait- it is naturally formed, narrow, typically navigable waterway that connects two larger bodies of water. Isthmus- it is a narrow strip of land connecting two large land areas otherwise separated by sea.

49. Gulf- it is portion of the ocean that penetrates land. Archipelago- a chain or group of island that is group together

50. Caldera- a bowl-shaped circular depression caused by the destruction of the peak of a volcano. Desert - an area with a little precipitation

51. Epicentre- the point on the earth’s surface directly above the hypocentre, where the energy of an earthquake is first released. Erosion- forces that shape the earth’s surface. Includes water, wind and ice.

52. Estuary- the end of a river when it meets the sea; Geologic time- the calendar of the earth’s history since it’s birth 4.6 billion years ago…

53. Glacier- a large mass of ice that moves over the land, carving and eroding surfaces as it moves. Globe- a spherical model of the earth’s surface that includes a map of the earth.

54. Cartogram- a “map” that is used to present statistical information. Cartography- the art and science of making maps.

55. Census- an investigation or count of a population. Demography- the study of population statistics and trends, such as births, deaths, and disease.

56. Equator- zero degree latitude divides the earth into the Northern and Southern hemispheres Latitude - angular degrees based on the equator,

57. Longitude- angular degrees based on the Prime meridian Map- a graphic representation of the earth’s surface.

58. Region- an area which is marked common characteristics Prime meridian- zero degrees longitude, also known as the G reenwhich meridian.

59. Ecological Footprints

60. Ecological Footprint Is a measure of human demand on the earth’s ecosystems. It is a standardized measure of demand for natural capital that may be contrasted with planet’s ecological capacity to regenerate. It represents the amount of biologically productive land and sea area necessary to supply the resources a human population consumes, and to assimilate associated waste.

61. Understanding Ecological F ootprint Ecological footprints helps in analyzing the pressure on our planet and ecological footprint analysis can be a useful tool to educate people to manage our ecological assets more wisely and take collective action to make sure that a nation’s demand for products and services remain within its borders.

62. How does the ecological footprint work? The ecological footprint essentially measures the supply and demand on nature. This means that on the supply side, biocapacity represents the natural productive land areas. Theses includes forests, fisheries, pastures and cropland. When left uninterrupted or unexploited these areas have the capacity to absorb almost all the waste produced by humans particularly carbon emissions.

63. Negative Effects of Ecological Footprint: Carbon emissions Lack of fresh air Global warming Increased environmental pollution Depletion of natural resources

64. For some perspectives, some ecological footprints of several countries are listed below. These values were listed for the year 2017 in the Global Footprint Network’s Open Data Platform: The units for ecological footprints are global hectares ( gha ) United States: 8.0 gha /person Russia : 5.5 gha /person Switzerland : 4.5 gha /person Japan : 4.7 gha /person France: 4.6 gha /person China : 3.7gha/person Indonesia: 1.7gha/person

65. According to Global Footprint Network, if everyone lived the lifestyle of the average American US citizen i.e. similar eating, transportation, living, and consumption habits, we need 5 planets to support ourselves.

66. Note that ecological footprints can be counterbalance by biocapacity , which refers to the ability of a biologically productive area to continuously generate renewable resources and clean up its wastes . An area is considered unsustainable if a land’s ecological footprint is greater than its biocapacity .

67. Simple steps to reduce your ecological footprint: Don’t drive when there is an alternative Reduce energy use Eat local, organic and in season foods Eat less meat and dairy Use less water

68. Concepts of Ecosystems

69. Ecosystem Is a community or group of living organism that live in and interact with each other in a specific environment.

70. Types of Ecosystems Natural Ecosystems Artificial/Man-made Ecosystems

71. 1. Natural Ecosystems: These ecosystems are capable of operating and maintaining themselves without any major interference by man. Terrestrial Ecosystems: Forest, Grassland, and desert Aquatic Ecosystems: marine and fresh water

72. 2. Artificial Ecosystem: These are maintained by man. These are manipulated by man for different purposes, e.g., croplands, artificial lakes and reservoirs, townships and cities.

73. Basic structure of an Ecosystem: Every ecosystem has n on-living ( abiotic ) and living ( biotic ) components.

74. Abiotic Components: Air Soil Temperature Light Water Minerals

75. Biotic Components: a. Autotrophic components (Producers )- this component is mainly constituted by green plants, algae and all photosynthetic organisms. b . Heterotrophic component (Consumers- the members of this component cannot make their own food. They consume the matter built by producers and are therefore called as consumers.

76. c. Decomposers- heterotrophic organisms chiefly bacteria and fungi that breakdown the complex compounds of dead protoplasm, and release simple substances usable by the producers are called decomposers or reducers. Collectively we call them as micro consumers.

77. The Subdivision of Ecology

78. Ecology can subdivided into two: Synecology (plant sociology/general ecology)- Syn means together. Synecology is the study of groups of organisms in relation to biotic and abiotic factors. Autecology (physiological ecology/ applied ecology)- Aut means self. Autecology is concerned with the responses of our individual organisms to temperature, moisture, light, nutrients and other factors of the environment.

79. Evolutions of Ecosystems

80. Ecosystem A geographic area where plants, animals, and other organism as well as weather and landscape, work together to form a bubble of life. Ecosystem contain biotic or living components as well as abiotic or the non-living components.

81. In nature, vegetation or plant communities are changing from time to time. In the same place, the replacement of the old plant community by a new plant community is called vegetation succession. Similarly, an ecosystem is replaced by another ecosystem, which we call the ecosystem evolution.

82. The history of earth is divided into four great eons, starting 4,540 million years ago ( mya ) with the formation of the planet. Each eon saw the most significant changes in earth’s composition. Climate and life. It means abiotic and biotic components.

83. Four Great Eons: Hadean eon Archean eon Proterozoic eon Phanerozoic eon

84. Hadean Eon (4540-4000 mya )

85. Hadean Eon (4540-4000 mya ) Represents the time before a reliable record of life; it began with the formation of the planet and ended 4.0 billion years ago. The earth is formed out of debris around the solar protoplanetary disk. There is no life. Temperatures are extremely hot, with frequent volcanic activity and hellish-looking environments (hence the eon’s name, which comes from Hades). The atmosphere is nebular. Possible early oceans or bodies of liquid water.

86. Archean (4000-2500 mya )

87. Archean (4000-2500 mya ) Prokaryote life, the first form of life, emerges at the very beginning of this eon, in a process known as abiogenesis. The continents of Ur, Vaalbara and Kenorland may have existed around this time. The atmosphere is composed of volcanic and green house gases.

88. Proterozoic (2500-541 mya )

89. Proterozoic (2500-541 mya ) The name of this eon means “early life”. Eukaryotes, a more complex form of life, emerge, including some forms of multicellular organisms. Bacteria begin producing oxygen, shaping the third and current earth’s atmosphere. Plants, later animals and possibly earlier forms of fungi form around this time. The early and late phases of this eon mat have undergone “Snowball Earth” periods, in which all of the planet suffered below-zero temperatures. The early continents of Columbia, Rodinia and Pannotia , in that order may have existed in this eon.

90. Phanerozoic (541-present)

91. Phanerozoic (541-present) Complex life, including vertebrates, begin to dominate the earth’s ocean in a process known as the Cambrian Explosion. Pangaea forms and later dissolves into Laurasia and Gondwana , which in turn dissolve in the current continents. Gradually life expands to land and familiar forms of plants, animals and fungi begin appearing, including annelids, insects and reptiles, hence the eon’s name which means “visible life”. Several mass extinctions occur, among which birds, the descendants of non-avian dinosaurs, and more recently mammals emerge. Modern animals- including humans-evolve at the most recent phases of this eon.